activity
20202026
most citedElemental abundances of nearby M dwarfs based on high-resolution near-infrared spectra obtained by the Subaru/IRD survey: Proof of concept

30 citations · 89 across the 12 of their papers we have counts for

collaborators

12 papers

astro-ph.IM2026

PyIRD: A Python-Based Data Reduction Pipeline for Subaru/IRD and REACH

Yui Kasagi, Hajime Kawahara, Ziying Gu +4

PyIRD is a Python-based pipeline for reducing spectroscopic data obtained with IRD (InfraRed Doppler; Kotani et al. (2018)) and REACH (Rigorous Exoplanetary Atmosphere Characteriza…

astro-ph.EP2025

Unveiling the Atmosphere of HR 7672 B from the Near-Infrared High-Resolution Spectrum Using REACH/Subaru

Yui Kasagi, Yui Kawashima, Hajime Kawahara +12

Characterizing the atmospheres of exoplanets and brown dwarfs is crucial for understanding their atmospheric physics and chemistry, searching for biosignatures, and investigating t…

astro-ph.SR2024

Weighing Single-lined Spectroscopic Binaries Using Tidal Effects on Radial Velocities: The Case of V723 Monocerotis

Mio Tomoyoshi, Kento Masuda, Teruyuki Hirano +6

In single-lined spectroscopic binaries (SB1s) where flux variations due to tidal deformation of the primary star (ellipsoidal variations, EVs) are detected, the binary mass can be…

astro-ph.EP2024★ 2 cited

Atmospheric retrieval of Subaru/IRD high-resolution spectrum of the archetype T-type brown dwarf Gl 229 B

Yui Kawashima, Hajime Kawahara, Yui Kasagi +14

Brown dwarfs provide a unique opportunity to study atmospheres and their physical and chemical processes with high precision, especially in temperature ranges relevant to exoplanet…

astro-ph.EP2024★ 3 cited

Differentiable Modeling of Planet and Substellar Atmosphere: High-Resolution Emission, Transmission, and Reflection Spectroscopy with ExoJAX2

Hajime Kawahara, Yui Kawashima, Shotaro Tada +11

Modeling based on differentiable programming holds great promise for astronomy, enabling advanced techniques such as gradient-based posterior sampling and optimization. This paradi…

astro-ph.EP2024★ 22 cited

Gliese 12 b: A temperate Earth-sized planet at 12 pc ideal for atmospheric transmission spectroscopy

M. Kuzuhara, A. Fukui, J. H. Livingston +103

Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the atmospheres of terrestrial planets via follow-up spectroscopic observ…

astro-ph.SR2023★ 4 cited

Direct Imaging Explorations for Companions around Mid-Late M Stars from the Subaru/IRD Strategic Program

Taichi Uyama, Charles Beichman, Masayuki Kuzuhara +32

The Subaru telescope is currently performing a strategic program (SSP) using the high-precision near-infrared (NIR) spectrometer IRD to search for exoplanets around nearby mid/late…

astro-ph.EP2023★ 9 cited

An Earth-sized Planet around an M5 Dwarf Star at 22 pc

Teruyuki Hirano, Fei Dai, John H. Livingston +46

We report on the discovery of an Earth-sized transiting planet () in a day orbit around K2-415 (EPIC 211414619), an M5V star at 22 pc. The pla…

astro-ph.EP2022★ 17 cited

A Super-Earth Orbiting Near the Inner Edge of the Habitable Zone around the M4.5-dwarf Ross 508

Hiroki Harakawa, Takuya Takarada, Yui Kasagi +46

We report the near-infrared radial-velocity (RV) discovery of a super-Earth planet on a 10.77-day orbit around the M4.5 dwarf Ross 508 (). Using precision RVs f…

astro-ph.EP2022★ 1 cited

Dippers from TESS Full-frame Images. II. Spectroscopic Characterization of Four Young Dippers

Yui Kasagi, Takayuki Kotani, Hajime Kawahara +9

Photometric monitoring by the Transiting Exoplanet Survey Satellite (TESS) has discovered not only periodic signals by transiting exoplanets but also episodic or quasi-periodic dim…

astro-ph.SR2021★ 30 cited

Elemental abundances of nearby M dwarfs based on high-resolution near-infrared spectra obtained by the Subaru/IRD survey: Proof of concept

Hiroyuki Tako Ishikawa, Wako Aoki, Teruyuki Hirano +24

Detailed chemical analyses of M dwarfs are scarce but necessary to constrain the formation environment and internal structure of planets being found around them. We present element…

astro-ph.EP2020★ 1 cited

Dippers from the TESS Full-Frame Images I: The Results of the first 1 year data and Discovery of A Runaway dipper

Tomoyuki Tajiri, Hajime Kawahara, Masataka Aizawa +9

We present a comprehensive catalog of the dippers---young stellar objects that exhibit episodic dimming---derived from the one year's worth of data of Transiting Exoplanet Survey S…